How to get date_diff from previous rows in Presto?

Question

I'm trying to get a diff_date from Presto from this data.

timespent | 2016-04-09T00:09:07.232Z | 1000          | general
timespent | 2016-04-09T00:09:17.217Z | 10000         | general
timespent | 2016-04-09T00:13:27.123Z | 250000        | general
timespent | 2016-04-09T00:44:21.166Z | 1144020654000 | general

This is my query

select _t, date_diff('second', from_iso8601_timestamp(_ts), SELECT from_iso8601_timestamp(f._ts) from logs f 
              where f._t = 'timespent'
               and f.dt = '2016-04-09'
               and f.uid = 'd2de01a1-8f78-49ce-a065-276c0c24661b'
               order by _ts)
from logs d
where _t = 'timespent'
and dt = '2016-04-09'
and uid = 'd2de01a1-8f78-49ce-a065-276c0c24661b'
order by _ts;

This is the error I get

Query 20160411_150853_00318_fmb4r failed: line 1:61: no viable alternative at input 'SELECT'

Answer 1

I think you want lag():

select _t,
       date_diff('second', from_iso8601_timestamp(_ts),
                 lag(from_iso8601_timestamp(f._ts)) over (partition by uid order by dt)
                )
from logs d
where _t = 'timespent' and dt = '2016-04-09' and
      uid = 'd2de01a1-8f78-49ce-a065-276c0c24661b'
order by _ts;